Electric furnace.



E. STASSANO.

ELECTRIC FURNACE.

APPLICATION FILED AUG. 7, 1911.

1,024,657, Patented Apr. 30, 1912,

2 SHEETS-SHEBT 1.

E. STASSANO.

ELECTRIC FURNACE.

APPLICATION FILED AUG. 71 1911.

Patenlzea Apr. 30, 1912.

2 SHEETSSHEET 2.

1 7506 2([0/ a l "475 a O ll/jj/ Wdrzessea 4 ERNESTO STASS AQNO, OFTURI'N, ITALY.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Apr. 30, 1912.

Application filed August 7, 1911. Serial No. 642,837.

T 0 all whom it may concern:

Be it known that I, ERNESTO STASSANO, subject of the King of Italy,residing at Turin, Italy, have invented certain new and usefulImprovements in Electric Furnaces, of which the following is aspecification.

This invention relates to electric furnaces in which the melting chamberis adapted to' be oscillated around two axes mutually perpendicular. andconsists in improved construction the obg'ect of which is that themaximum thermal energy resulting rom the transformation into heat, bythe aid of the voltaic arc, of the electric energy may be utilized in.metallurgical operations and es pecially in the metallurgy of iron.

The invention comprises essentially the mounting and control of thefurnace chamher so as to obtain a perfect stirring of the whole chargeby imparting to the chamber a simple oscillatory movement, the form ofthe closed chamber affording both a concentration of heat on the chargeand a hydraulic control and cooling of the electrodes.

On the accompanying drawings is shown, by way of example, one form ofconstruction for this type of furnace, and Figure 1 is a verticalsection of the furnace along the axis; Fig. 2 is a horizontal section online a-l') of Fig. 1; Fig. 3 shows a modified form of the furnacechamber, especially suitable for furnaces of large capacity; Figs. d, 5,8 and 7 show, diagrammatically, arrange ments of electrodes fordifferent kinds of current employed; Fig. 8 is a longitudinal sectionalong the line 0 (Z of Fig. 10 of a hydraulically controlledelectrode-carrier provided with cooling means; Fig. 9 is a section alonge-; of Fig. 8; Fig. 10 is a front view of the head of theelectrode-carrier; Figs. 11 and 12 are front and side views of a valvefor the automatic control of the electrode; Fig. 13 is a section alongg-Jt of Fig. ll and Fig. 14- is a section along 23-Z of Fig. 12.

As will be seen from Figs. 1 and 2, the furnace comprises a casing ofsheet iron or other material, inclosing a melting chamher 2 ofrefractory material which has, in

l the case of small furnaces, the form of a hollow sphere with the lowerportion thereof cut away by a plane constituting the bot tom ofthe-furnace (Fig. 1) while with fur naces of large dimensions, theinterior cavity has preferably the form of an ellipsoid alternatingtwo-phase current.

with the bottom similarly formed in the lower portion. The termspheroidal is used in the claims as a generic term covering either thespherical or ellipsodial form. This form of furnace chamber has theadvantage that the walls of refractory material are rendered moreresisting and are reinforced by a filling or envelop 3 of refractoryearth, and at the same time the chamber serves to revcrberate better onto the charge the heat emanating from the are or arcs.

The wall of chamber 2 is pierced with holes for the electrodes 4:disposed at a certain inclination, as shown in Fig. 1, for the purposeof directing the are on to the charge and at such a height that theywill not contact therewith. The number of elec trodes can be variedaccording to the type of current adopted and the size and power of thefurnace; thus in furnaces of small capacity two electrodes suflice ifthe current be a continuous or an alternating single phase current (Fig.i) and three suiiice in the case where the furnace is heated by athree-phase current (Fig. 5). In furnaces of greater capacity four orSlX electrodes (Figs. 6 and 7) may be used, giving two or threeindependent arcs distributed through the furnace as shown in the drawing.

Furnaces with four electrodes may be heated either by a continuouscurrent or an alternating monophase current (in which case the two arcsare parallel) or again by an Furnaces with six electrodes can be heatedby a continuous current by alternating single phase or alternating threephase currents. In the wall of the chamber 2 is a charging opening 5,and on an extension of the bottom is a tapping outlet 6. The chargingopening is closed by two closure members 7 and 8 of which one 7 is ofrefractory material and reaches to the inner end of the opening and theother 8 is of metal and is at the outer en The mounting of the furnaceis effected as followsz-At two diametrically opposite points of thecasing 1 are two pivots 9 mounted in two supports 10 rigidly con nectedwith a ring 11 encircling the casing and having two pivots 12 arrangedat 90 with respect to the pivots 9. The pivots 12 are supported by thestandards 13, which in the construction shown in Fig. 1 are connectedtogether by the stirrup 14 passing below the bottom of the furnace.

As will be easily understood, the furnace .chamber is so suspended thatits vertical axis can assume any inclination to the vertical. The casing1 has depending from its lower end a pivot 15 the axis of whichcoincides with that, of the casing. The end of this pivot is rounded andhas a bearing in a groove or socket formed in a member 16 adjustablymounted on a spoke of a wheel 17 journaled on the stirrup 1-1. The wheel17 can be rotated by any suitable means, for instance by means of teethon its periphery engaging a pinion 18 operated by means of the shaft 19,worm gearing 20 and a small electric motor not shown.

By turning the wheel 17 on its axis the pivot 15 is displaced in acircle so that the axis of the furnace traces out a cone with a circularbase. This movement, by reason of the double suspension of the chamber,imparts a rdtat-ive movement to the molten mass contained in chamber 2,which movement may be continuous or intermittent corresponding tothe-motion of the wheel 17. The wheel can if necessary be turnedalternately first in one direction and then in another.

In every case the furnace oscillates simply on the pivots 9 and 12 andconsequently as far as concerns the stirring up of the metal to berefined the furnace operates as if it were a rotary furnace but withregard to the leading inof the current, the cooling and the control ofthe electrodes, a simple oscillating furnace. The electrodes 4 have attheir rear ends a metal sleeve or coupling 21, to which is attached thecontrolling rod 22 (Fig. 9) connected by means of the cross bar 23 toother rods 24, 25, 26 which carry an annular member or piston 27 adaptedto be displaced in the annular space 28 formed in the wall of thecylindrical chamber 29 through the central hole of which passes theelectrode. The cylinder 29 constitutes the cooling chamber for the jointof the electrode. In the annular space 28 of cylinder 29 is establisheda continuous circulation of water regulated so as to control the electrode by displacing the piston 27 in one direction or in the other,which piston is connected by means of the rods 24, 25, 26 to theelectrode-carrier 22. For this purpose in the two portions of theannular space 28 separated by the piston 27, are two independentcirculations of water, one from the pipe 30 (communicating with thespace 28) through the space 28, hole 31, formed in the piston 27, andthe hollow rod 24; the other through rod 25 also hollow, the hole 32 inthe said rod, the space 28 and the pipe 33 v to outside.

It will be understood that if the discharge of water by the hollow rod24 is stopped, the pressure of the water reaching the space 28 by pipe30 will displace the piston '27 toward the right and consequently alsothe electrode, while if the water discharging by pipe 33 is stopped thewater arriving at the right extremity of the annular space 28 throughthe hollow rod 23, will displace the piston 27 toward the left.

To'control the water circulation, a double cock, allowing either the twodischarging pipes to remain open at the same time or one to be closed,may be used. This cock comprises a fixed hollow truncated conical casing34 from which branch the discharge ducts 24 and 33 communicating withthe discharge pipes 24 and 33 and from which also branch thecorresponding pipes 24" and 23". The plug 34 is divided up into twochambers by a longitudinal partition 36 and is provided with elongatedoutlets 37, 37, 38, 38 whereby the discharge ducts are put incommunication with the internal chambers of the plug. The plug isoperated by means of a lever 39 which may be actuated by hand orautomatically. hen lever 39 is turned, for example to a verticalposition, as shown in Fig. 11, water passes from ducts 24', 33 to ducts2 1", 33 across the outlets 37, 37 and 38, 38', cto '(Z, and circulatesfreely. If on the contrary the lever 39 is turned to the left thecommunication of duct 24 with the inside of the plug is interruptedwhile water from duct 33' con tinues to pass across the outlets 37, 3'7and consequently is discharged (Fig. 14).

When the pressure increases on the left end of the annular piston 27,the electrode is displaced toward the right. If on the contrary thelever 39 is turned to the right, the discharge from duct 33 is stoppedand the pressure of water increases on the right end of piston 27 whichmoves to displace the electrode to the left. The pressure of the watermay be varied from atmosphere to a maximum of 1 atmosphere.

The ducts which lead it to the cylinders of the several electrodes areof flexible piping, for as the furnace oscillates there is no need forspecial joints. For the same reason the feed of the electrical energy tothe electrodes does not necessitate rubbing contacts but only flexiblecables grouped with the piping for the water on a support fixed to thebase of the apparatus.

hat I claim as my invention and desire to secure by Letters Patent is 1.In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfrom the lower end of the chamber and engaged by a rotating member in aneccentric point of said rotating member.

2. In an electric furnace a closed melting chamber of spheroidal formwith the lower portion cut away by a plane constitutingthe bottom of thechamber, said chamber being arranged in a casing mounted to oscillate ina ring, pivots supporting said ring at an angle of 90 with respect tothepivots of the casing and an arm depending axially from the lower end ofthe chamber and engaged by a rotating member in an eccentric point ofsaid rotating member.

3. In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfrom the lower end of the chamber and engaged by a rotating member in aneccentric point of said rotating member, electrodes mounted in chambersprovided with water jackets, flexible cables for feeding the current tothe electrodes and flexible piping for feeding the water to the water jackets'of the electrodes chambers.

4. In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfroin the lower end of the chamber and engaged by a rotating member'inan eccentric point of said rotating member, electrodes mounted inchambers provided with water jackets, an annular piston sliding in thewater jacket, means for connecting said piston with the electrode andmeans for operating the piston by controlling the circulation of waterin the water jackets.

'5. In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfrom the lower end of the chamber and engaged by a rotating member in aneccentric point of the said member, electrodes mounted in chambersjackets, an annular piston sliding in the water jackets, hollow rodsconnecting the said annular piston with the cross bars of theelectrodes, each of said hollow rods communicating with one of the twoportions provided with water separated by the piston in the waterjacket, and means for controlling the circulation of water in said twoportions of the water jackets.

6. In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfrom the lower end of the chamber and engaged by a rotating member in aneccentric point of the said member, electrodes mounted in chambersprovided with water jackets, an annular piston sliding in the waterjackets, hollow rods connecting the said annular piston with the crossbars of the electrode, each of the hollow rods communicating with one ofthe portions separated by the piston in the water jackets, twoindependent circulations of water in the said chambers, a double cockfor controlling the circulation of water and also the displacement ofthe annular piston.

7. In an electric furnace a closed melting chamber arranged in a casingmounted to oscillate in a ring, pivots supporting said ring at an angleof 90 with respect to the pivots of the casing, an arm depending axiallyfrom the lower end of the chamber and engaged by a rotating member in aneccentric point of the said member, electrodes mounted in chambersprovided with water jackets, an annular piston sliding in the waterjacket, hollow rods connecting the said annular piston withthe cross barof the electrodes, each of the hollow rods communicating with one of thechambers formed by the piston in the water jacket, two independentcirculations of water in the said chambers, a double cock mounted on thepiping for the feeding of water, a plug divided up into two chambers bya longitudinal partition and allowing to stop one or the other of thecirculations, and means for operating said plug.

In testimony whereof I afiix my signature in presence of two witnesses.

ERNESTO STASSANO.

Witnesses PIERO GIANOLIO, CARLO TORBAY.

